1. Field
This invention is generally related to solar systems, and in particular, to solar systems utilized to melt industrial materials.
2. Related Art
There is a need to improve the energy efficiency associated with heating and/or melting industrial materials at industrial volumes. At present in the United States (“US”), melting industrial materials entails a large quantity of energy with aluminum fabrication alone accounting for about 30% of that energy consumption. An even greater amount of energy is required when recycled steel is added. As such, major US industries, especially those industries related to metal recycling and stock material fabrication, occupy a major portion of the nation's total energy consumption. Therefore, for nearly every industry involved in the process of fabrication or recycling of existing materials, there is a need for high amounts of energy to melt materials, heat the materials, or for other key stage, or stages, of the process.
In general, the two major problems with conventional heating (e.g., known furnaces (also known as burners) utilize gas, induction, blast, and electric arc furnaces (“EAFs”)) are their dependence on limited and fossil fuels (e.g., coal, oil, and natural gas), as well as the inefficiencies in how they transfer the generated thermal energy to heat a material. It is appreciated by those of ordinary skill in the art that these types of furnaces have significant energy losses during the thermal energy transfer process (i.e., the process of heating the furnace and then utilizing that heat to melt or heat the material), which ultimately results in about 30 to 40% efficiency. This results generally because large amounts of energy input into a furnace does not directly translate to thermal energy. As an example in a blast furnace, requires massive quantities of input energy to raise its temperature to its operating temperature. In aluminum melting, for example, only about 40% of the energy utilized by the furnace goes to actually melting the aluminum.
This problem is also similar for furnaces utilizing induction melting, which is done typically open to air. Electrical resistance furnaces (“ERTs”) that utilize the principle of indirect heating are capable of utilizing about 40% of their input energy for melting but in practice are only typically about 26% efficient because ERT furnaces typically experience other energy losses that include heating the air and then losing hot air through ventilation conduction to the insulating liner of the furnace and losses of energy when opening the ERT furnace. As a result, EAF furnaces require large quantities of electrical power and can have adverse environmental effects. Additionally, in many EAF furnaces additionally gas burners are typically utilized to assist in heat scrap metal to a temperature where the metal conducts electricity efficiently so as allow the EAF furnace to run properly. Moreover, another major issue with these types of furnaces is the large carbon cost of the process where the amount of carbon dioxide output by these systems. Unfortunately, their continued use is largely due to the relatively cheap cost of current sources of fuel.
Attempts to address and solve these problems utilizing “green energy” (i.e., renewable energy sources) have yet to materialize. Known uses of solar energy are not capable of addressing or solving these problems because known solar technologies are limited in their capacity, window of operation, and overall efficiency when capturing solar energy and transferring it into a usable fashion. Specifically, known solar systems have a number of inefficiencies in how they utilize solar energy to either heat an object or generate electricity. These solar cells placed on solar panels utilize photovoltaic cells to convert solar energy impinging on the solar cell into electricity. Common modernly used crystalline silicon solar cells output on average about 18% energy conversion due to losses of heat and the electricity transfer within the solar cells.
In addition to solar cells, modern solar systems also include systems that heat objects, such as water pipes for example, that transfer the resulting heat energy to other objects for heating those objects or generating electricity through movement of, for example, water through the pipes to a turbine. Moreover, another problem with solar energy is that it is not concentrated enough in any given area to use on an industrial scale or it requires a system in place to utilize the energy in a process which converts it to useable electricity.
Attempts to solve these problems have includes using solar reflector systems to attempt to reflect and focus energy into a small area that may either generate power with a solar cell, heat water to generate electricity through a turbine, or heat a small crucible containing some material in a small furnace. However, even with the use of reflectors, the resulting system still do not have high efficiency. The ones the utilize solar cells still only have 18% efficiency. The ones that heat water still have the same thermal loses as the non-reflector solar heating systems. Additionally, the small furnaces lose energy from having to heat a crucible. Moreover, all of these solar reflector systems lose energy from transferring energy to additional components in the system and from reflection angle losses. Furthermore, some of these system are stationary in a way that does not allow them to follow the Sun and, therefore, limits the amount of time that they may operate. As a result, without a change to modern solar energy capability, solar energy cannot currently compete on a commercial scale and switching to such a technology would not be a cost benefit for most industries.
This is unfortunate because solar energy is a free resource which would over long periods of time, pay for itself in any application that can properly capture and transfer solar energy into a usable fashion. As such, there is a need for solar energy capture system that is capable of producing a sufficient amount of energy for use in modern industrial processes that include heating or melting of industrial materials.